1. Field of the Invention
The present invention relates to a method for performing optimal recording power calibration (OPC) and a recording medium therefor, which can enable an OPC operation to be quickly performed in a recorder for recording data on a recording medium, such as a digital versatile disc-rewritable (DVD-RW).
2. Description of the Related Art
Recently, high-density recording mediums capable of permanently recording high-quality video and audio data, for example, digital versatile discs-rewritable (DVDs-RW), have been developed, commercialized and supplied. Furthermore, recorders such as DVD-recorders for recording and reproducing data on the DVDs-RW have been developed, commercialized and supplied.
As shown in FIG. 1, a power calibration area (PCA) necessary for performing an optimal recording power calibration (OPC) operation and a recording management area (RMA) are assigned to a DVD-RW. The PCA and the RMA are positioned before a lead-in zone.
For example, when a recorder such as a DVD-recorder receives a recording command based upon a user request, a set of OPC operations for recording data on a recording medium normally is automatically performed. The set of OPC operations includes a recording operation of predetermined test data in the PCA and an adjustment operation of a recording power value so that a beta ratio value indicating an asymmetry ratio of a radio frequency (RF) signal read and detected, according to the recorded test data, is close to zero. In this case, one error correction code (ECC) block having a size of 16 sectors within the PCA is used from an outer circumference direction to an inner circumference direction.
Further, the RMA can contain, for example, 28 recording management data (RMD) blocks in which recording related data associated with an OPC operation is recorded. As shown in FIG. 2, format 1 RMD, format 2 RMD and format 3 RMD defined in the DVD-RW contain 15 fields (Field 0 ˜Field 14) that have a record size of one sector.
The second field (Field 1) for the format 1 RMD contains OPC related information. As shown in FIG. 3, the second field (Field 1) for the format 1 RMD contains four sections (Nos. 1, 2, 3 and 4) in which unique drive manufacturer identities (IDs) corresponding to a plurality of different recorders performing OPC operations are recorded.
And the four sections contain recording power information and time stamps along with the different drive manufacturer IDs (e.g., A_drive, B_drive, C_drive and D_drive). Furthermore, the four sections contain power calibration addresses having a predetermined record size, e.g., a record size of 4 bytes, as information indicating recording positions of the PCA in which test data is recorded according to OPC operations performed by the different recorders.
Where OPC operations are performed in the recorder, such as the conventional DVD-RW, power calibration addresses having a record size of 4 bytes are read from the four sections of the RMD block and the read power calibration addresses are temporarily stored in the recorder. The power calibration addresses are compared with one another, and a recording position of the PCA in which the last test data is recorded is retrieved. As described above, the test data is sequentially recorded in one ECC block having a size of 16 sectors from an outer circumference direction to an inner circumference direction. A power calibration address having the smallest value indicates recording position information associated with the last test data.
The power calibration addresses recorded in the four sections of the RMD block are read and compared so that a recording position of the last test data can be retrieved. In other words, it is necessary to find the address with the smallest value. This process is time consuming, and hence delays the beginning of the OPC operations. In order for the power calibration addresses having a record size of 4 bytes to be compared with one another, there is a problem in that the recorder must include a plurality of registers having a size of 4 bytes therein.